SUPPLEMENTAL CASH FLOW INFORMATION (Supplemental Information Referable to Consolidated Statements of Cash Flows) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
SUPPLEMENTAL CASH FLOW INFORMATION [Abstract]
Interest (exclusive of amount capitalized)	$ 2,715,000	$ 21,869,000
Income taxes	6,486,000	2,062,000
Accrued liabilities for purchases of property, plant & equipment	25,880,000	13,340,000
Accrued liabilities for common stock purchases	3,164,000	0
Fair value of noncash assets and liabilities exchanged	$ 0	$ 20,000,000